Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Rio Grande City it's a good idea to determine when to plant bidens.

Planting Calendar for Bidens

Frost tolerance for bidens:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You really shouldn't plant bidens until after all chance of frost has passed because they require warm weather.

The earliest that you can plant bidens in Rio Grande City is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant bidens and expect a good harvest is probably September. If you wait any later than that and your bidens may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your bidens indoors.

Last Frost Date

On average the last frost is on February 15 in Rio Grande City. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Rio Grande City is just an average the actual date of last frost is different every year. Half of the time in Rio Grande City it frosts late in the year after February 15 so make sure that you are prepared to cover your bidens if you have one of those late frosts.

USDA Zone Info for Rio Grande City

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Rio Grande City

You may be interested in your other planting guides for Rio Grande City.